I don't think heat transfer through the pano roof can be completely eliminated. With a material, you can do various coatings, etc. that block IR transmission through it. Something that is solid to visible light is usually also solid to IR (though there are materials that looks solid to visible light, but will let IR through). This is what you get with the standard roof. It is opaque to IR, UV, and visible light, it's a property of aluminum and paint.
However, there is also a factor of IR absorption and that is largely a matter of color. Something that is silver or white will tend to reflect most energy at or around the visible spectrum. White objects are white because they reflect back the full spectrum of visible light. Light colored objects also tend to radiate heat back to the atmosphere at a lower rate than darker colors. If you're out at night when frost is just beginning to form on cars, you will see it on dark windshields and dark cars before the white ones begin frosting up on their painted surfaces. Plant leaves are green because green is the only shade of light the leaves don't use and reflect back.
The pano roof is black and it will absorb infrared when the sun shines on it. It may not transmit much through, but it will become like a glass cooktop radiating the heat it has absorbed. So I would expect a pano roof car will heat up more sitting in the sun than a solid roof car would because of IR absorption.
IR absorption is the reason I am thinking about a white Tesla, though the pano roof's extra couple of inches of headroom might be nice. I got to sit in a Tesla for the first time this afternoon and it had the pano roof. I could see where the standard roof might be a bit claustrophobic by comparison.
BTW, the people on this forum are awesome. I had some concerns about legroom (I have very long legs) and a forum member met me so I could adjust the seats and see if they worked (quite well!) and I got a chance to drive it a few blocks. We were talking about having to wait a year to save up enough money, but my SO is now talking about selling some vacant land she has to speed up the process. She's beginning to chomp at the bit (I'm wearing the bit out from chomping). She was going to sell it anyway, but it was on the back burner.